A thrilled Earl of Wessex spoke of his delight yesterday at the news that he and his wife are expecting their first baby.

The Countess of Wessex, 38, is due to give birth in December. The baby will be eighth in line to the throne.

Sophie was supposed to join her husband on an official trip to Devon but pulled out after doctors advised her not to undertake engagements.

Instead she spent the day at their home, Bagshot Park in Surrey.

Speaking to well-wishers outside Laura House in Totnes, a centre for adults with learning disabilities, Edward said he was "thrilled and delighted".

"I can't tell you very much more about it," he said. "There's a first time for everything, I suppose.

"She has been told that she has got to take it very easy. That is the doctor's orders and she is not going to disobey."

A spokeswoman for the Countess said she was feeling a little tired but was absolutely fine.

The happy announcement follows the trauma of a failed pregnancy. In December 2001, the Countess was airlifted to hospital after suffering an ectopic pregnancy.

She underwent a two-and-a-half-hour operation during which surgeons removed the foetus from a Fallopian tube. At the time, doctors said that if the condition had continued undiagnosed, it could have been life-threatening.

Sophie spoke of her sadness at losing their first baby but said she was optimistic the couple could still start a family.

"I'm obviously very sad, but it was just not meant to be," she said at the time. "But there will be other chances."

When the couple married in June 1999, they agreed with the Queen that any children would not be styled HRH but would have courtesy titles as sons or daughters of an earl.

Their eldest son would become Viscount Severn and other sons would have the title The Honourable. Daughters would carry the title of Lady. The baby will be the seventh grandchild for the Queen and the Duke of Edinburgh, who were told the news - along with the Countess's parents - at the weekend.